Close to 60% of the world population has at least one mobile telephone subscription, a number which is expected to further increase up to ˜90% by the year 2015. About two-thirds of these mobile phones are actually being used in the developing world, which holds significant promise for various telemedicine applications potentially impacting the fight against several global health problems. The use of the existing or built-in hardware and/or software architecture contained in mobile phones to improve healthcare is a recently emerging theme, which has already enabled implementation of various telemedicine technologies on mobile devices including electrical impedance tomography, electrocardiography, fluorescent microscopy, and lens-free on-chip microscopy.
Among these technologies, fluorescent microscopy is particularly important since fluorescent markers have gone through a significant advancement over the last decade bringing specificity and sensitivity to various lab-on-a-chip applications including, for example, diagnosis of disease, quantification of target cells/bacteria, or detection of biomarkers. Breslauer et al. has recently demonstrated fluorescent microscopy on a mobile phone that achieves ˜1.2 μm resolution across a field-of-view (FOV) of ˜0.025 mm2 using a rather large and bulky opto-mechanical attachment that is more than 15 cm in length. See Breslauer D N et al., Mobile Phone Based Clinical Microscopy for Global Health Applications, PLoS ONE 4(7) (2009). The device described in Breslauer et al. uses an LED light source together with conventional optics components including microscope objectives, eyepiece, emission and excitation filters that are positioned in-line which results in the long length of the device. There is still a need for higher throughput platforms that can image much larger sample areas and volumes using more compact and lighter weight telemedicine interfaces. Moreover, prior efforts such as that disclosed in Breslauer et al. generate images of static volumes. There is a need for translating flow-based fluorescent cytometry concepts into small mobile devices. A small imaging flow cytometry device could extend micro-analysis capabilities in resource limited settings to such applications as, for example, conducting whole blood analysis or screening of water-borne parasites in drinking water.